OBJECTIVE: The purpose of our study was to assess the relationship between time intervals of CT examinations and the stages of hepatocellular carcinomas (HCCs) detected during the surveillance of patients with liver cirrhosis.
MATERIALS AND METHODS: In this study, 73 patients with 93 HCCs (reference standard: surgery, n=7 [8 HCCs]; biopsy, n=2 [3 HCCs]; imaging criteria, n=64 [82 HCCs]) who showed no evidence of HCC on prior CT examinations were included. Patients were stratified into three groups based on the time interval between the two CT examinations: groups A (interval≤1 year, n=21), B (interval between 1 and 2 years, n=25), and C (interval≥2 years, n=27). Tumor stages according to the American Joint Committee on Cancer (AJCC), the Barcelona Clinic Liver Cancer (BCLC) staging system, and the Milan criteria were evaluated retrospectively by two reviewers. The Fisher exact test was used to compare tumor stages. Spearman correlation coefficients were used to assess the correlation between the CT interval and tumor size.
RESULTS: One (4%) HCC in group B and four (15%) HCCs in group C were larger than 5 cm in diameter, whereas no tumor was larger than 3 cm in diameter in group A. There was no difference in tumor diameter between groups, but tumor size was positively correlated with time interval between examinations (Spearman correlation coefficient, 0.472; p<0.001). In group A, 19 (90%) patients had cancers categorized as T1, and the remaining patients had cancers categorized as T2. In group B, one (4%) patient had a cancer that was categorized as T3b according to the AJCC classification, in the intermediate stage according to the BCLC classification, and above the Milan criteria. In group C, three (11%) patients had T3b cancers, and five had cancers in either intermediate or higher stage and above the Milan criteria.
CONCLUSION: HCC detected on CT performed within 1 year of a negative examination was at a curable stage in patients with liver cirrhosis.